A cutting device of substrate is illustrated in FIG. 1. Upon a cutter wheel assembly 1 running across a surface of a substrate 2, it may generate substrate material debris 20. To prevent the debris 20 from remaining at the cutting line, an air ejection device 19 is enabled during a cutting process to allow the debris 20 sputtering into surroundings. However, it still inevitably remains some debris 20 on the surface of the substrate.